1. Field of the Invention
The present invention is relative to an apparatus concerning a directional fin of the type that one uses on a sail board, on a drifter, on a floating board without a sail called "surfboard", or the same on the lateral floats of a trimaran hull boat.
2. Prior Art
One knows that a device of this type, for example a sail board, comprises at the back at the least a fin which is found submerged vertically in the water under the back of the floating hull. Most of the time, such a fin is fixed.